As things are currently packaged, you cannot install the group
deepin-extras unless you manually exclude the package,
This is due to the fact that upstream,
deepin-wallpapers is a split package, but in Manjaro it is a single monolithic package. Because of this, @oberon updated the
deepin-wallpapers package to both conflict with and provide
deepin-community-wallpapers. This resolves the issue of file overlap but creates the problem with the extras group install because it creates an unresolvable conflict.
I suppose, the argument could be made that the end-user should manually figure out to exclude the package but it seems like there are a lot of ways to fix it so that they wouldn’t need to.